Science DOES change with age.
For instance, Newton thought he had cracked gravity. Einstein demonstrated that some important parts were missing and even now, the scientifically known relationship between mass and gravity cannot explain galaxies. So there is still more to be discovered.
There was a time when science did not know about atoms. It was called an atom because the word means indivisible. Then they divided it! Then they split what that had just split once before.
The scientific consensus was that land masses were stationary but Wegener thought the continents moved about. The consensus scientists rubbished him for about half a century until after he was dead before they recognised that he was, in fact, right.
Is light a particle as Newton thought, or a wave that would explain Young's Slit experiment, or a particle again as Einstein thought with his photoelectric effect or both or neither or something else ... ?
Climate alarmists have a list of criteria that they have to work through. If what you say is "on message" i.e. suitably alarmist, then you get a free pass to say whatever you want but if you are off-message then they work down a list until they find a criterion that you can't match then they say: "Aha! This is rubbish because ..."
The list is:
1. Is the source "on message"? If so believe completely and ignore any possible concerns.
2. If the source is not "on message" then a wrong answer to any of the following will permit the information to be dismissed out of hand:
a) Do we know the original source?
b) If so, is the source an approved one?
c) Was it peer-reviewed?
d) Where the reviewers "approved"?
e) Did the person have a PhD?
f) Was the PhD in one of the approved subjects?
g) Can he or she be associated with a "non-approved" person or organisation like Heartland, for instance?
h) Have they ever been associated with funding from a "non-approved" source like Big Oil or Big Tobacco.
i) Are they just spokespeople for someone with an opposing view?
j) If you run out of ideas check Sourcewatch.
k) If all else fails, they can be dismissed because they are not "on-message". When using this option try to include a strawman argument to appeal to the faithful.